Utility poles commonly support high voltage power lines, cable TV cables, and telephone wires. Typically, the poles are owned by a power company and the power company charges the other utility companies an annual fee for each pole connection. For example, a CATV company might pay to the power company that owns and maintains the poles a fee of $10.00 per year for each pole connection.
To avoid pole-connection expenses, it is a common practice to lash new cables to old cables already in position. Special tools are available that travel along the existing cable and play out a lashing wire that spirals around a new cable to lash it to the existing line as the new cable is pulled along the path of the existing line.
The new cable is pulled along the existing cable by a device known as an overlash jig. The jig includes a roller that rollingly engages the existing line. The jig is towed by a vehicle so it rolls along the existing line pulling the new wire at the same speed the vehicle is moving. The towing is accomplished by a rope that extends from the vehicle to the jig.
When an obstacle such as a utility pole, a tree limb or a mid-span drop is encountered, the vehicle is stopped and the towing rope is disconnected from the jig at the jig end thereof. An effort is then made to hold the new cable in position while the obstacle is circumvented. The free end of the tow rope is brought around, over or under the obstacle as conditions require and it is re-connected to the jig so that the vehicle can resume its forward travel, again towing the jig and hence pulling the new cable. When the re-connection has been made, the means holding the new cable into position is released.
The primary drawback of the above-described procedure is the lack of any suitable means for holding the new cable during the time the towing rope is released from the jig. If the new cable has been pulled a very short distance when the first obstacle is encountered, one person can simply hold the new cable during the re-positioning of the tow rope around the obstacle. However, once the new cable has been pulled over a considerable distance, its weight is such that it can no longer be manually held into position. Accordingly, inventors have developed numerous clamps designed to clamp the new cable to the old cable during the time the tow rope is disconnected.
The use of such clamps has two important shortcomings. First of all, their use is labor-intensive, i.e., it takes time to apply the clamps, and to remove them once the tow rope has been re-connected. Secondly, and even more seriously, the known clamps simply do not work well. The new cable, even when tightly clamped, will slip. The resultant slack will block driveways, intersections and the like. If the clamps are tightened more and more in an effort to stop the backward slipping and the resultant slack, the clamps will damage both the old and new cables.
As optical fibers become increasingly important, thousands of miles of cables containing such fibers are being strung. There has been instances where vehicles have struck sagging cables and destroyed many miles thereof. There is a need for a cable puller that eliminates the clamps of the prior art so that the slippage and sagging problem is overcome, but the prior art, taken as a whole, neither teaches nor suggests how an improved jig could be built.